1. Field of the Invention
The present invention relates to a sliding door, and more particularly to a sliding door having a spring biasing device for recovering door panels automatically.
2. Description of the Prior Art
Typical sliding doors or folding doors or other closure door devices comprise a number of door panels slidably attached to upper and lower tracks with wheels or rollers, to allowing the door panels to slide along the upper and the lower tracks freely.
For example, U.S. Pat. No. 4,799,528 to Benitez, and U.S. Pat. No. 5,065,807 to Maeda et al. disclose two of the typical sliding doors or folding doors or other closure door devices each also comprising a number of door panels slidably attached to upper and lower tracks with roller bearings. However, after opening or moving the door panels, the users have also to move the door panels back to the original positions manually.
U.S. Pat. No. 5,085,261 to Bortoluzzi discloses another typical sliding door or folding door comprising a number of foldable accordion door panels slidably attached to tracks with roller bearings, and return springs coupled between lugs of spacer elements. However, the return springs are directly coupled between the lugs of the spacer elements of the door panels, such that the moving strokes of the door panels are limited by the stretchability or extensibility of the return springs.
For example, when the return springs are made stronger, the stretchability or extensibility of the return springs will be greatly decreased. On the contrary, when the return springs are made weaker, the stretchability or extensibility of the return springs may be increased, but the door panels may not be suitably recovered by the return springs.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional sliding doors or folding doors.